OData Dart
OData Dart is a library to make fetching data from OData Rest APIs slightly easier. (Slightly 😅)
Compatibility
Compatible with OData v4.0 and v4.01
Usability
Not usable for production, this version is experimental
Usage
To get data, you will create queries first. There are 2 types of queries, Query<T> and ColletionQuery<T>.
final instance = OData("api.example.com/v1");
final ODataResponse simpleExample = await instance
.single("/api/Person(1)") // Returns Query
.select("Oid, Name, Age, Phone") // Sets $select fields, fields are seperated by comma. Returns the Query (URL QUERY => $select=Oid,Name,Age,Phone)
.expand("Facebook") // Sets $expand field, you may use multiple expands, but must set one at a time. (URL QUERY => $expand=Facebook)
.fetch(); // Fetches [baseUrl]/api/Person(1)?$select=Oid,Name,Age,Phone&$expand=Facebook
final ODataResponse<LoginDetails> loginExample = await instance
.single(
"api/Authentication/Login",
options: QueryOptions(
method: "POST",
requestBody: {
"Username": "TestUser1234", // I don't like how C# standardizes capitalized variable names :((((
"Password": "••••••••",
},
convertor: (json) => LoginDetails.fromJson(json),
)
)
.fetch();
// You need to set Cookie and the Bearer if needed.
instance.setBearer(loginExample.data.token);
instance.setCookie(loginExample.response.headers["set-cookie"]); // Now Bearer token and Cookie are appended in the request HEADER by default. Set QueryOptions.tryUseAuth to false to omit it from the header
final ODataResponse<Person> convertorExample = await instance
.single(
"/api/Person(1)",
options: QueryOptions(
convertor: (json) => Person.fromJson(json),
))
.select("Oid, Name, Age, Phone")
.expand("Facebook")
.fetch();
final ODataCollectionResponse<Person> complexExample = await instance
.collection(
"/api/Person",
tryUseAuth: false,
options: CollectionQueryOptions(
tryUseAuth: false, // When true, adds Cookie and Bearer token in the header if available. True by default.
convertor: (json) => Person.fromJson(json), // Convertor function; must pass convertor for single instance.
),
) // Returns CollectionQuery<T>
.select("Oid,Username,Name,Age"),
// .selectList(["Oid", "Username", "Name", "Age"]) // Alternative option
.expand(
"ConnectedAccounts"
.expand() // This creates ExpandQueryField(), which is special class to handle nested $expand, $select, etc.
.select("Oid") // This selects single field, "Oid", from /api/Person/ModifiedBy
.expand("Facebook".expand()) //
.expand("Google".expand().select("email")))
.count() // This ensures @odata.count is included in collection queries
.fetch();